ID   HETR_LEPBY              Reviewed;         299 AA.
AC   Q93CE8; O30610;
DT   24-MAY-2004, integrated into UniProtKB/Swiss-Prot.
DT   01-DEC-2001, sequence version 1.
DT   03-AUG-2022, entry version 40.
DE   RecName: Full=DNA-binding transcriptional activator HetR {ECO:0000255|HAMAP-Rule:MF_00781};
DE            EC=3.4.21.- {ECO:0000255|HAMAP-Rule:MF_00781};
GN   Name=hetR {ECO:0000255|HAMAP-Rule:MF_00781, ECO:0000303|PubMed:9835026};
OS   Leptolyngbya boryana (Plectonema boryanum).
OC   Bacteria; Cyanobacteria; Pseudanabaenales; Leptolyngbyaceae; Leptolyngbya.
OX   NCBI_TaxID=1184;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=ATCC 18200 / UTEX 594 / PCC 73110;
RX   PubMed=12151106; DOI=10.1016/s0167-4781(02)00399-8;
RA   Schiefer W., Schuetz K., Hachtel W., Happe T.;
RT   "Molecular cloning and characterization of hetR genes from filamentous
RT   cyanobacteria.";
RL   Biochim. Biophys. Acta 1577:139-143(2002).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 54-202, AND DOES NOT FORM HETEROCYSTS.
RC   STRAIN=ATCC 18200 / UTEX 594 / PCC 73110;
RX   PubMed=9835026; DOI=10.1111/j.1574-6968.1998.tb13270.x;
RA   Janson S., Matveyev A., Bergman B.;
RT   "The presence and expression of hetR in the non-heterocystous
RT   cyanobacterium Symploca PCC 8002.";
RL   FEMS Microbiol. Lett. 168:173-179(1998).
RN   [3]
RP   DOES NOT FORM HETEROCYSTS.
RC   STRAIN=ATCC 18200 / UTEX 594 / PCC 73110;
RX   PubMed=10712536; DOI=10.1104/pp.122.3.731;
RA   Misra H.S., Tuli R.;
RT   "Differential expression of photosynthesis and nitrogen fixation genes in
RT   the cyanobacterium Plectonema boryanum.";
RL   Plant Physiol. 122:731-736(2000).
CC   -!- FUNCTION: Might be involved in temporal and/or spatial regulation of
CC       nitrogen fixation. Dimerization is required for DNA-binding. Has both a
CC       protease and a DNA-binding activity. {ECO:0000255|HAMAP-Rule:MF_00781}.
CC   -!- SUBUNIT: Homodimer; disulfide-linked. {ECO:0000255|HAMAP-
CC       Rule:MF_00781}.
CC   -!- MISCELLANEOUS: This filamentous cyanobacterium does not make
CC       heterocysts. In anaerobic conditions under continuous light it
CC       temporally alternates between photosynthesis and nitrogen-fixing with a
CC       periodicity of about 15 hours. Transcription of a number of
CC       photosynthetic and nitrogen-fixing genes cycles alternatively with the
CC       same periodicity. {ECO:0000269|PubMed:10712536,
CC       ECO:0000305|PubMed:9835026}.
CC   -!- SIMILARITY: Belongs to the peptidase S48 family. {ECO:0000255|HAMAP-
CC       Rule:MF_00781}.
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DR   EMBL; AF410433; AAL05046.1; -; Genomic_DNA.
DR   EMBL; AF013036; AAB81944.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q93CE8; -.
DR   SMR; Q93CE8; -.
DR   MEROPS; S48.001; -.
DR   GO; GO:0003677; F:DNA binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0004252; F:serine-type endopeptidase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0043158; P:heterocyst differentiation; IEA:InterPro.
DR   GO; GO:0006508; P:proteolysis; IEA:UniProtKB-KW.
DR   Gene3D; 1.10.10.1670; -; 1.
DR   Gene3D; 1.10.10.1680; -; 1.
DR   HAMAP; MF_00781; HetR; 1.
DR   InterPro; IPR040949; HetR_C.
DR   InterPro; IPR041936; HetR_DNA-bd_N.
DR   InterPro; IPR041935; HetR_flap.
DR   InterPro; IPR005319; Pept_S48_HetR.
DR   Pfam; PF18460; HetR_C; 1.
DR   Pfam; PF03574; Peptidase_S48; 1.
PE   3: Inferred from homology;
KW   Activator; Disulfide bond; DNA-binding; Hydrolase; Protease;
KW   Serine protease; Transcription; Transcription regulation.
FT   CHAIN           1..299
FT                   /note="DNA-binding transcriptional activator HetR"
FT                   /id="PRO_0000208482"
FT   ACT_SITE        152
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00781"
FT   DISULFID        48
FT                   /note="Interchain"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00781"
FT   CONFLICT        187..188
FT                   /note="KR -> NG (in Ref. 2; AAB81944)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   299 AA;  34692 MW;  D5E085166BC74CD6 CRC64;
     MTNDLDLIKL LSPSAMDQIM LYLAFSAMRT GGHRHGAFLD AAATAAKCAI YMTYLEQDGN
     IRMTGHLHHI EPKRVKAIVE EVRQALTEGK LLKMLGSQEP RYLIQLPYVW MEQYPWQPGR
     SRVPGTSLTS EEKRQIEQKL PNNLPDAQLI NSFQFLELIE FLNTRSQEDL PPEQRMPLSE
     ALAEHIKRRL LYSGTVTRIE SPWGMPFYAL TRASYSPEDQ EERAYVMIED TARFFRLMQD
     WAKREDQVMR VLEELDIPDD RVRDAIAELD EILRNWADRY HQEGGKPFVV QMVFGSTET